IntroductionDespite a high potential of endothelial progenitor cells (EPCs) for diagnostic purposes, the EPC role in developing ischemic chronic heart failure (CHF) has not been determined obviously.The objective of this study was to assess the counts of CD45+CD34+, CD45−CD34+, CD14+CD309+, and CD14+CD309+Tie2+ phenotyped circulating EPCs of various subpopulations in patients with ischemic CHF. Methods and ResultsThe study involved 153 patients (86 male), aged 48–62 years, with angiographically proven coronary artery disease (CAD) and 25 healthy volunteers. CHF was diagnosed in 109 patients (71.2%). Mononuclear cell populations were phenotyped by flow cytofluorimetry. Cardiovascular risk factors, such as type 2 diabetes mellitus, hyperlipidemia, arterial hypertension, and adherence to smoking, may have a negative effect on circulating EPC counts in CAD patients regardless of the presence of CHF. The depletion of the CD14+CD309+- and CD14+CD309+Tie2+-phenotyped circulating EPC counts is associated with the severity of left ventricular dysfunction, whereas the CD45+CD34+- and CD45−CD34+-mononuclear cell counts are more representative of the severity of atherosclerotic coronary artery lesions. ConclusionThe authors found that New York Heart Association functional class of CHF, left ventricular ejection fraction <42%, the N-terminal pro–B-type natriuretic peptide level >554 pg/mL, and Е/Еm ratio >15 U had the highest predictive value for the depletion of the EPC count in CAD patients.